The present invention relates to an exposure apparatus.
A PLZT electro-optical device is known to produce an electro-optical effect of varying its double refracting characteristics in accord with an applied voltage and thus, is used as an optical shutter. Conventional exposure apparatuses employ such PLZT optical shutters for controlling an exposure through optical modulation with the application of different voltages.
However, the disadvantage of such conventional exposure apparatuses is that although line exposure is feasible during movement of a photosensitive material, the PLZT optical shutter when closed cannot perfectly prevent the passing of light to the photosensitive material which remains stationary. Particularly when a light source remains turned on, a leak of light from the PLZT optical shutter reaches the photosensitive material causing unwanted exposure. Also, the conventional exposure apparatuses offer only monotone exposure.